In a wave on a string, the amplitude is the maximum displacement of a point on the string from its equilibrium position. What is the amplitude of an electromagnetic wave?

Estimate the wavelength of your favorite radio station.

An electromagnetic wave has S = 3 x 10^-6 W/m². How many joules of energy are transmitted into a 2 m x 2 m square during one minute?

Estimate the frequency of an electromagnetic wave with wavelength equal to your height. What kind of wave is this?